Crop water productivity modeling: Demand and impact at a field level Example: On-site Impacts- Water Demand and Water Productivity Activities Model Used Estimate WR and consumption of crops grown under different soils Climates: CROPWAT (vr. 8) AquaCrop (Vr. 4) Current Vs alternative AWM scenarios

Example: CWR and Consumption of crops grown on Vertisols under current and alternative AWM scenarios

Example 1: WR, Consumption and WP of wheat grown on BBF and Flat seedbeds Location and year Growing season eff. rainfall (m3 ha-1) Actual ETc (m3 ha-1) Grain WP with respect to eff. rainfall (kg m-3) WP with respect to actual ETc (kg m-3) BBF Flat % increase due to BBF Enewari 1986 4770 3005 1086 0.23 0.22 5 0.37 0.99 Dogollo 1986 5740 3161 2582 0.32 45 0.58 0.49 Dejen 1987 5640 3000 1200 0.16 38 0.42 0.77 Bahir Dar 2007 7570 2804 2429 0.34 0.26 31 0.93 0.82 Merawi 2007 5720 3135 1206 0.30 0.10 200 0.54 0.50 Bichena 1997 0.19 79 0.53 0.83 Average 5876 3040 1669 0.33 0.24 57 0.66 0.89 BBF and Flat beds planted on July 1 and August 15, respectively

Crop type: Pasture (extensive grazing) Example 2: WR, Consumption and WP of rice, grass-pea and extensively grazed grass grown on flat areas Crop type: Rice  Location Yield (kg ha-1) Average eff. rain (m3 ha-1) Actual ETc (m3 ha-1) Grain WP (kg m-3) with respect to Biomass WP with respect to eff. rain Grain Straw Eff. rain Actual ETc   Fogera 2007 3510 4467 6330 5259 0.55 0.67 1.3 Fogera 2011 3744 4765 4233 0.59 0.88 3627 4616 4746 0.57 0.78 Pawe 2007 3644 4638 7900 4953 0.46 0.74 1.0 Pawe 2008 3547 4514 5857 0.45 0.61  Average 3596 4576 5405 0.68  Crop type: Grass -pea  3130 4930 4860 4662 9558 4895 0.95 1.8 Crop type: Pasture (extensive grazing)  Fogera 2011* Biomass (kg ha-1) Eff. rain (m3 ha-1) CWR (m3 ha-1) Biomass WP (kg m-3) with respect to Actual ETc 2793 1940 1.44 0.44

Impacts Use of BBF increased water demand, but reduced evaporation loss BBF increased WP with respect to effective rainfall Growing rice instead of grass-pea or grazing increased water demand, but reduced evaporation Use of BBF on drainable and rice on flat land increased Economic Water Productivity